1. Field of the Invention
The present invention relates to a technology for extracting a snapshot from data stored in a storage unit of a program executing apparatus.
2. Description of the Related Art
When a failure occurs in a server system, dump information including data used at the time of the failure is extracted from a memory or a virtual memory, and is saved into a storage unit such as a magnetic disk.
However, the server system can only be recovered after saving all of the dump information stored in the memory in the storage unit. Accordingly, the server system cannot immediately resume a service.
Japanese Patent Application Laid Open No. 2001-290677 discloses an operation server and a standby server. When a failure occurs in the operation server, dump information of the operation server is sent to the standby server. The standby server is used to stores the dump information and also to recover the operation server.
Japanese Patent Application Laid Open No. H7-234808 discloses a redundant main memory in a server. When a failure occurs in the server, the redundant main memory is partitioned into two main memories. One main memory is used to recover the server, while the other main memory is used to retain dump information.
However, the problem with the conventional technology is that data in a memory cannot be efficiently extracted at an arbitrary timing.
Specifically, in the technology disclosed in Japanese Patent Application Laid Open No. 2001-290677, the dump information stored in the operation server needs to be sent back to the standby server. If there is a delay in sending the dump information, the recovery of the operation server is also delayed.
In the technology disclosed in Japanese Patent Application Laid Open No. H7-234808, the redundant main memory is partitioned after the dump information is acquired. Accordingly, to acquire dump information again at an arbitrary timing, the partitioned memories need to be made redundant again. This requires a significant amount of time and cost.